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排序方式: 共有147条查询结果,搜索用时 15 毫秒
71.
Abrams GS Adolphsen CE Aleksan R Alexander JP Averill D Ballam J Barish BC Barklow T Barnett BA Bartelt J Bethke S Blockus D de Boer W Bonvicini G Boyarski A Brabson B Breakstone A Brom JM Bulos F Burchat PR Burke DL Cence RJ Chapman J Chmeissani M Cords D Coupal DP Dauncey P DeStaebler HC Dorfan DE Dorfan JM Drell PS Drewer DC Elia R Fay J Feldman GJ Fernandes D Field RC Ford WT Fordham C Frey R Fujino D Gan KK Gero E Gidal G Glanzman T Goldhaber G Gomez Cadenas JJ Gratta G Grindhammer G 《Physical review letters》1989,63(15):1558-1561
72.
Abrams GS Adolphsen CE Averill D Ballam J Barish BC Barklow T Barnett BA Bartelt J Bethke S Blockus D Bonvicini G Boyarski A Brabson B Breakstone A Brom JM Bulos F Burchat PR Burke DL Cence RJ Chapman J Chmeissani M Cords D Coupal DP Dauncey P DeStaebler HC Dorfan DE Dorfan JM Drewer DC Elia R Feldman GJ Fernandes D Field RC Ford WT Fordham C Frey R Fujino D Gan KK Gero E Gidal G Glanzman T Goldhaber G Gomez Cadenas JJ Gratta G Grindhammer G Grosse-Wiesmann P Hanson G Harr R Harral B Harris FA 《Physical review letters》1989,63(20):2173-2176
73.
Abrams GS Adolphsen CE Aleksan R Alexander JP Allen MA Atwood WB Averill D Ballam J Bambade P Barish BC Barklow T Barnett BA Bartelt J Bethke S Blockus D de Boer W Bonvicini G Boyarski A Brabson B Breakstone A Breidenbach M Brom JM Brown JL Brown KL Bulos F Burchat PR Burke DL Cence RJ Chapman J Chmeissani M Clendenin J Cords D Coupal DP Dauncey P Dean NR DeStaebler HC Dorfan DE Dorfan JM Drell PS Drewer DC Dydak F Ecklund S Elia R Erickson RA Fay J Feldman GJ Fernandes D Field RC Fieguth TH 《Physical review letters》1989,63(7):724-727
74.
The Role of Reduced Graphite Oxide in Transition Metal Oxide Nanocomposites Used as Li Anode Material: An Operando Study on CoFe2O4/rGO
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Stefan Permien Dr. Sylvio Indris Gero Neubüser Andy Fiedler Prof. Dr. Lorenz Kienle Dr. Stefan Zander Dr. Stephen Doyle Björn Richter Prof. Dr. Wolfgang Bensch 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16929-16938
A composite consisting of CoFe2O4 spinel nanoparticles and reduced graphite oxide (rGO) is studied as an anode material during Li uptake and release by applying synchrotron operando X‐ray diffraction (XRD) and operando X‐ray absorption spectroscopy (XAS), yielding a comprehensive picture of the reaction mechanisms. In the early stages of Li uptake, a monoxide is formed as an intermediate phase containing Fe2+ and Co2+ ions; this observation is in contrast to reaction pathways proposed in the literature. In the fully discharged state, metallic Co and Fe nanoparticles are embedded in an amorphous Li2O matrix. During charge, metallic Co and Fe are oxidized simultaneously to Co2+ and Fe3+, respectively, thus enabling a high and stable capacity to be achieved. Here, evidence is presented that the rGO acts as a support for the nanoparticles and prevents the particles from contact loss. The operando investigations are complemented by TEM, Raman spectroscopy, galvanostatic cycling, and cyclic voltammetry. 相似文献
75.
Yuen Au Yeung Gero Friesecke Bernd Schmidt 《Calculus of Variations and Partial Differential Equations》2012,44(1-2):81-100
We investigate ground state configurations of atomic systems in two dimensions interacting via short range pair potentials. As the number of particles tends to infinity, we show that low-energy configurations converge to a macroscopic cluster of finite surface area and constant density, the latter being given by the density of atoms per unit volume in the triangular lattice. In the special case of the Heitmann–Radin sticky disc potential and exact ground states, we show that the macroscopic cluster has a (unique) Wulff shape. This is done by showing that the atomistic energy of crystalline configurations, after subtracting off a bulk part and re-scaling, Gamma-converges to a macroscopic anisotropic surface energy. 相似文献
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Asymptotics-based configuration-interaction (CI) methods [G. Friesecke and B. D. Goddard, Multiscale Model. Simul. 7, 1876 (2009)] are a class of CI methods for atoms which reproduce, at fixed finite subspace dimension, the exact Schro?dinger eigenstates in the limit of fixed electron number and large nuclear charge. Here we develop, implement, and apply to 3d transition metal atoms an efficient and accurate algorithm for asymptotics-based CI. Efficiency gains come from exact (symbolic) decomposition of the CI space into irreducible symmetry subspaces at essentially linear computational cost in the number of radial subshells with fixed angular momentum, use of reduced density matrices in order to avoid having to store wave functions, and use of Slater-type orbitals (STOs). The required Coulomb integrals for STOs are evaluated in closed form, with the help of Hankel matrices, Fourier analysis, and residue calculus. Applications to 3d transition metal atoms are in good agreement with experimental data. In particular, we reproduce the anomalous magnetic moment and orbital filling of chromium in the otherwise regular series Ca, Sc, Ti, V, Cr. 相似文献
79.
Abbott AP El Ttaib K Frisch G Ryder KS Weston D 《Physical chemistry chemical physics : PCCP》2012,14(7):2443-2449
Silver is an important metal for electronic connectors, however, it is extremely soft and wear can be a significant issue. This paper describes how improved wear resistant silver coatings can be obtained from the electrolytic deposition of silver from a solution of AgCl in an ethylene glycol/choline chloride based Deep Eutectic Solvent. An up to 10-fold decrease in the wear volume is observed by the incorporation of SiC or Al(2)O(3) particles. The work also addresses the fundamental aspect of speciation of silver chloride in solution using EXAFS to probe solution structure. The size but not the nature of the composite particles is seen to change the morphology and grain size of the silver deposit. Grain sizes are shown to be consistent with previous nucleation studies. The addition of LiF is found to significantly affect the deposit morphology and improve wear resistance. 相似文献
80.
We present here novel insight into exchange‐correlation functionals in density functional theory, based on the viewpoint of optimal transport. We show that in the case of two electrons and in the semiclassical limit, the exact exchange‐correlation functional reduces to a very interesting functional that depends on an optimal transport map T associated with a given density ρ. The limit problem has been suggested, on grounds of formal arguments, in the physics literature, but it appears that it has not hitherto been interpreted as an optimal transport problem. Since the above limit is strongly correlated, the limit functional yields insight into electron correlations. We prove the existence and uniqueness of such an optimal map for any number of electrons and each ρ and determine the map explicitly in the case when ρ is radially symmetric. © 2012 Wiley Periodicals, Inc. 相似文献